Co-author Adam Wolf, from Princeton University's Department of Ecology and Evolutionary Biology, explained: "On today's planet, the supply of nutrients in the soil is determined by river deposits or nutrients that are airborne."
Researchers say the model can also forecast the consequences of losing today's large animals.
But Dr. Wolf added that their study suggested that things were once very different: "We believe that large animals once

DAVIS — Two species of bacteria living on the ocean floor have teamed up in a unique symbiotic relationship to form a critical link in the Earth’s nitrogen cycle, reports a research team that includes two University of California, Davis, microbiologists.
The scientists, led by researchers affiliated with the University of Southern California, will publish their findings about the novel bacterial partnership Aug. 8 in the journal Nature.
At the heart of the study are the long, thin,

Environmental awareness comes in many forms. Often, it is shaped by an understanding of science or public policy, but it also can be informed by religion. Rarely, however, do all three of these perspectives intersect at once—and that is the challenge two Yale University professors, Mary Evelyn Tucker and John Grim, have been addressing for the past three decades.
Tucker and Grim’s course “Religion, Ecology, and Cosmology” illustrates how religion, spirituality,

The oscillations during the past 2.5 million years between ice ages and interglacials were probably triggered by orbital changes, but the observed amplitude and timing of these climate cycles still awaits a full explanation. One notable correlation links lower partial pressure (or concentration) of CO2 with ice ages: changes in CO2 concentration may cause some of the ice-age cooling, but what causes the loss of CO2 is unknown. Daniel Sigman, Mathis Hain and Gerald Haug review the evidence in sup

A new report should spur public debate about how science and technology can best sustain the earth while furthering the goals of humanity, according to Robert Socolow, one of 18 maverick thinkers convened by the National Academy of Engineering (NAE) to map the greatest technological challenges of this century.